/* Support macros for making weak and strong aliases for symbols,
and for using symbol sets and linker warnings with GNU ld.
-Copyright (C) 1995 Free Software Foundation, Inc.
+Copyright (C) 1995, 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
We include config.h which is generated by configure.
It should define for us the following symbols:
+ * HAVE_ASM_SET_DIRECTIVE if we have `.set B, A' instead of `A = B'.
+ * ASM_GLOBAL_DIRECTIVE with `.globl' or `.global'.
* HAVE_GNU_LD if using GNU ld, with support for weak symbols in a.out,
and for symbol set and warning messages extensions in a.out and ELF.
- This implies HAVE_WEAK_SYMBOLS; set by --with-gnu-ld.
- * HAVE_ELF if using ELF, which supports weak symbols.
- This implies HAVE_WEAK_SYMBOLS; set by --with-elf.
-
- * HAVE_WEAK_SYMBOLS if weak symbols are available in the assembler and
- linker being used. Set by --with-weak-symbols.
+ * HAVE_ELF if using ELF, which supports weak symbols using `.weak'.
+ * HAVE_ASM_WEAK_DIRECTIVE if we have weak symbols using `.weak'.
+ * HAVE_ASM_WEAKEXT_DIRECTIVE if we have weak symbols using `.weakext'.
*/
+
+/* This is defined for the compilation of all C library code. features.h
+ tests this to avoid inclusion of stubs.h while compiling the library,
+ before stubs.h has been generated. Some library code that is shared
+ with other packages also tests this symbol to see if it is being
+ compiled as part of the C library. We must define this before including
+ config.h, because it makes some definitions conditional on whether libc
+ itself is being compiled, or just some generator program. */
+#define _LIBC 1
+
#include <config.h>
-/* This is defined for the compilation of all C library code.
- features.h tests this to avoid inclusion of stubs.h while
- compiling the library, before stubs.h has been generated.
- Some library code that is shared with other packages also
- tests this symbol to see if it is being compiled as part
- of the C library. */
-#define _LIBC
-
-/* The symbols in all the user (non-_) macros are C symbols. Predefined
- should be HAVE_WEAK_SYMBOLS and/or HAVE_ELF and/or HAVE_GNU_LD.
- HAVE_WEAK_SYMBOLS is implied by the other two. HAVE_GNU_LD without
- HAVE_ELF implies a.out. */
-
-#ifndef HAVE_WEAK_SYMBOLS
-#if defined (HAVE_ELF) || defined (HAVE_GNU_LD)
-#define HAVE_WEAK_SYMBOLS
+/* This disables sccsid/rcsid strings in lots of code of non-GNU origin. */
+#define lint 1
+/*
+\f
+*/
+
+#ifndef ASSEMBLER
+
+/* Define the macros `_' and `N_' for conveniently marking translatable
+ strings in the libc source code. */
+
+#define N_(msgid) msgid
+
+#include <libintl.h>
+extern const char _libc_intl_domainname[];
+
+#ifdef dgettext
+/* This is defined as an optimizing macro, so use it. */
+#define _(msgid) dgettext (_libc_intl_domainname, (msgid))
+#else
+/* Be sure to use only the __ name when `dgettext' is a plain function
+ instead of an optimizing macro. */
+#define _(msgid) __dgettext (_libc_intl_domainname, (msgid))
#endif
+
#endif
-#ifndef __SYMBOL_PREFIX
-#ifdef HAVE_ELF
-#define NO_UNDERSCORES
-#else
-#include <sysdep.h> /* Should define NO_UNDERSCORES. */
+/*
+\f
+*/
+/* The symbols in all the user (non-_) macros are C symbols.
+ HAVE_GNU_LD without HAVE_ELF implies a.out. */
+
+#if defined (HAVE_ASM_WEAK_DIRECTIVE) || defined (HAVE_ASM_WEAKEXT_DIRECTIVE)
+#define HAVE_WEAK_SYMBOLS
#endif
+
+#ifndef __SYMBOL_PREFIX
#ifdef NO_UNDERSCORES
#define __SYMBOL_PREFIX
#else
#endif
#endif
+
/* Define ALIAS as a strong alias for ORIGINAL. */
+#ifdef HAVE_ASM_SET_DIRECTIVE
#define strong_alias_asm(original, alias) \
+ ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias); \
.set C_SYMBOL_NAME (alias),C_SYMBOL_NAME (original)
#ifdef ASSEMBLER
#define strong_alias(original, alias) strong_alias_asm (original, alias)
#else
#define strong_alias(original, alias) \
- asm (".set " __SYMBOL_PREFIX #alias "," __SYMBOL_PREFIX #original);
+ asm (__string_1 (ASM_GLOBAL_DIRECTIVE) " " __SYMBOL_PREFIX #alias "\n" \
+ ".set " __SYMBOL_PREFIX #alias "," __SYMBOL_PREFIX #original);
+#endif
+#else
+#define strong_alias_asm(original, alias) \
+ ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME (alias); \
+ C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
+#ifdef ASSEMBLER
+#define strong_alias(original, alias) strong_alias_asm (original, alias)
+#else
+#define strong_alias(original, alias) \
+ asm (__string_1 (ASM_GLOBAL_DIRECTIVE) " " __SYMBOL_PREFIX #alias "\n" \
+ __SYMBOL_PREFIX #alias " = " __SYMBOL_PREFIX #original);
+#endif
#endif
-/* Define ALIAS as a weak alias for ORIGINAL.
- If weak aliases are not available, this defines a strong alias. */
+/* Helper macros used above. */
+#define __string_1(x) __string_0(x)
+#define __string_0(x) #x
+
+
#ifdef HAVE_WEAK_SYMBOLS
+
#ifdef ASSEMBLER
+
+#ifdef HAVE_ASM_WEAKEXT_DIRECTIVE
+
+/* Define ALIAS as a weak alias for ORIGINAL.
+ If weak aliases are not available, this defines a strong alias. */
+#define weak_alias(original, alias) \
+ .weakext C_SYMBOL_NAME (alias), C_SYMBOL_NAME (original)
+
+/* Declare SYMBOL to be weak. */
+#define weak_symbol(symbol) .weakext C_SYMBOL_NAME (symbol)
+
+#else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
+
+/* Define ALIAS as a weak alias for ORIGINAL.
+ If weak aliases are not available, this defines a strong alias. */
#define weak_alias(original, alias) \
.weak C_SYMBOL_NAME (alias); \
C_SYMBOL_NAME (alias) = C_SYMBOL_NAME (original)
-#else
+
+/* Declare SYMBOL to be weak. */
+#define weak_symbol(symbol) .weak C_SYMBOL_NAME (symbol)
+
+#endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
+
+#else /* ! ASSEMBLER */
+
+#ifdef HAVE_ASM_WEAKEXT_DIRECTIVE
+#define weak_symbol(symbol) asm (".weakext " __SYMBOL_PREFIX #symbol);
+#define weak_alias(original, alias) \
+ asm (".weakext " __SYMBOL_PREFIX #alias ", " __SYMBOL_PREFIX #original);
+#else /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
+#define weak_symbol(symbol) asm (".weak " __SYMBOL_PREFIX #symbol);
#define weak_alias(original, alias) \
asm (".weak " __SYMBOL_PREFIX #alias "\n" \
__SYMBOL_PREFIX #alias " = " __SYMBOL_PREFIX #original);
-#endif
+#endif /* ! HAVE_ASM_WEAKEXT_DIRECTIVE */
+#endif /* ! ASSEMBLER */
#else
#define weak_alias(original, alias) strong_alias(original, alias)
+#define weak_symbol(symbol) /* Do nothing. */
#endif
+#if (!defined (ASSEMBLER) && \
+ (__GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8)))
+/* GCC 2.8 and later has special syntax for weak symbols and aliases.
+ Using that is better when possible, because the compiler and assembler
+ are better clued in to what we are doing. */
+#undef strong_alias
+#define strong_alias(name, aliasname) \
+ __typeof (name) aliasname __attribute__ ((alias (#name)));
+
+#ifdef HAVE_WEAK_SYMBOLS
+#undef weak_symbol
+#define weak_symbol(name) \
+ extern __typeof (name) name __attribute__ ((weak));
+#undef weak_alias
+#define weak_alias(name, aliasname) \
+ __typeof (name) aliasname __attribute__ ((weak, alias (#name)));
+#endif /* HAVE_WEAK_SYMBOLS. */
+#endif /* Not ASSEMBLER, and GCC 2.8 or later. */
-/* When the file using this macro is linked in, the linker
- will emit a warning message MSG. */
+
+
+/* When a reference to SYMBOL is encountered, the linker will emit a
+ warning message MSG. */
#ifdef HAVE_GNU_LD
#ifdef HAVE_ELF
-#define link_warning(msg) \
- static const char __evoke_link_warning__[] \
- __attribute__ ((section (".gnu.warning"))) = msg;
+#define link_warning(symbol, msg) \
+ static const char __evoke_link_warning_##symbol[] \
+ __attribute__ ((section (".gnu.warning." #symbol))) = msg;
#else
-#define link_warning(msg) \
+#define link_warning(symbol, msg) \
asm(".stabs \"" msg "\",30,0,0,0\n" \
- ".stabs \"__evoke_link_warning__\",1,0,0,0\n"\
- ".stabs \"__evoke_link_warning__\",2,0,0,0\n");
+ ".stabs \"" __SYMBOL_PREFIX #symbol "\",1,0,0,0\n");
#endif
#else
/* We will never be heard; they will all die horribly. */
-#define link_warning(msg)
+#define link_warning(symbol, msg)
#endif
/* A canned warning for sysdeps/stub functions. */
#define stub_warning(name) \
- link_warning ("warning: " #name " is not implemented and will always fail")
+ link_warning (name, \
+ "warning: " #name " is not implemented and will always fail")
+
+/*
\f
+*/
+
#ifdef HAVE_GNU_LD
/* Symbol set support macros. */
/* These are all done the same way in ELF.
There is a new section created for each set. */
+#ifdef PIC
+/* When building a shared library, make the set section writable,
+ because it will need to be relocated at run time anyway. */
+#define _elf_set_element(set, symbol) \
+ static const void *__elf_set_##set##_element_##symbol##__ \
+ __attribute__ ((unused, section (#set))) = &(symbol)
+#else
#define _elf_set_element(set, symbol) \
static const void *const __elf_set_##set##_element_##symbol##__ \
- __attribute__ ((section (#set))) = &(symbol)
+ __attribute__ ((unused, section (#set))) = &(symbol)
+#endif
/* Define SET as a symbol set. This may be required (it is in a.out) to
be able to use the set's contents. */
/* Declare SET for use in this module, if defined in another module. */
#define symbol_set_declare(set) \
- extern void *const __start_##set, *const __stop_##set;
+ extern void *const __start_##set __attribute__ ((__weak__)); \
+ extern void *const __stop_##set __attribute__ ((__weak__)); \
+ /* Gratuitously repeat weak decl, in case using broken GCC (<2.8). */\
+ weak_symbol (__start_##set) weak_symbol (__stop_##set)
/* Return a pointer (void *const *) to the first element of SET. */
#define symbol_set_first_element(set) (&__start_##set)
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